Search Publications
Irradiated atmospheres of accreting magnetic white dwarfs with an application to the polar AM Herculis
Gänsicke, B. T.; Beuermann, K.; König, M.
We present a pilot study of atmospheres of accreting magnetic white dwarfs irradiated by intense fluxes at ultraviolet to infrared wavelengths. The model uses a standard LTE stellar atmosphere code which is expanded by introducing an angle-dependent external radiation source. The present results are obtained for an external source with the spectra…
Outstanding aeronomy problems at Venus
Witasse, O.; Nagy, A. F.
Of all the non-terrestrial ionospheres and thermospheres in our solar system those of Venus have been explored and studied the most. This is mainly because of the 14 year exploration of the well-instrumented Pioneer Venus spacecraft and the theoretical studies prompted by the resulting observational information. However, there are still a number o…
Characterizing three candidate magnetic cataclysmic variables from SDSS: XMM-Newton and optical follow-up observations.
Szkody, P.; Henden, A.; Schmidt, G. D. +4 more
In the latest in our series of papers on XMM-Newton and ground-based optical follow-up of new candidate magnetic cataclysmic variables (mCVs) found in the Sloan Digital Sky Survey, we report classifications of three systems: SDSS J144659.95+025330.3, SDSS J205017.84-053626.8, and SDSS J210131.26+105251.5. Both the X-ray and optical fluxes of SDSS …
The non-constant slope of the C IV Baldwin effect in NGC 4151
Wang, R.; Han, J. L.; Wu, X. -B. +2 more
Context: .The relationship between the emission-line equivalent width and the continuum luminosity, called the Baldwin effect, is important for studies of the physics of the broad-line region of AGNs. Some recent studies have revealed the non-constant slope of the intrinsic Baldwin effect for several Seyfert 1 galaxies.
Aims: .Using the archiv…
The colour-magnitude relations of ClJ1226.9+3332, a massive cluster of galaxies at z = 0.89
Ebeling, H.; Jones, L. R.; Donovan, D. +2 more
The colour-magnitude relations (CMRs) of one of the most massive (~1015Msolar), high-redshift (z = 0.89) clusters of galaxies known have been studied. Photometry has been measured in the V, R, I, z, F606W, F814W, J and K bands to a depth of K ~ 20.5 = K* + 2.5 and spectroscopy confirms 27 K-band selected galaxies as members o…
Energetics and Dynamics of an Impulsive Flare on March 10, 2001
Sakao, Taro; Uddin, Wahab; Chandra, Ramesh +5 more
We present Hα observations from ARIES (Nainital) of a compact and impulsive solar flare that occurred on March 10, 2001 and which was associated with a CME. We have also analyzed HXT, SXT/Yohkoh observations as well as radio observations from the Nobeyama Radio Observatory to derive the energetics and dynamics of this impulsive flare. We coalign t…
On the multiwavelength spectrum of the microquasar 1E 1740.7-2942
Bassani, L.; Bazzano, A.; Del Santo, M. +3 more
Context: .The microquasar 1E 1740.7-2942 is a source located in the direction of the Galactic Center. It has been detected at X-rays, soft gamma-rays, and in the radio band, showing an extended radio component in the form of a double-sided jet. Although no optical counterpart has been found so far for 1E 1740.7-2942, its X-ray activity strongly po…
The Evaporation Regime in a Confined Flare
Maltagliati, L.; Teriaca, L.; Falchi, A.
We studied the evolution of a small eruptive flare (GOES class C1) from its onset phase using multi-wavelength observations that sample the flare atmosphere from the chromosphere to the corona. The main instruments involved were the Coronal Diagnostic Spectrometer (CDS) aboard SOHO and facilities at the Dunn Solar Tower of the National Solar Obser…
Mathematical Morphology: Star/Galaxy Differentiation & Galaxy Morphology Classification
Moore, Jason A.; Pimbblet, Kevin A.; Drinkwater, Michael J.
We present an application of Mathematical Morphology (MM) for the classification of astronomical objects, both for star/galaxy differentiation and galaxy morphology classification. We demonstrate that, for CCD images, 99.3+/-3.8% of galaxies can be separated from stars using MM, with 19.4+/-7.9% of the stars being misclassified. We demonstrate tha…
Suzaku Reveals Helium-burning Products in the X-Ray-emitting Planetary Nebula BD +30 3639
Hamaguchi, K.; Matsushita, K.; Hayashida, K. +7 more
BD +30 3639, the brightest planetary nebula at X-ray energies, was observed with Suzaku, an X-ray observatory launched on 2005 July 10. Using the X-ray Imaging Spectrometer, the K lines from C VI, O VII, and O VIII were resolved for the first time, and the C/O, N/O, and Ne/O abundance ratios were determined. The C/O and Ne/O abundance ratios excee…